Microbial resistance to conventional antimicrobial treatment is an ongoing concern to medical professionals. Until the problem of resistance is overcome, a steady supply of new treatments and therapies for treating microbial infections is required in order to blunt the effect of microbe mutations that render conventional therapies less effective or, in certain cases, ineffective. In particular, resistance to quinolone antibiotics is becoming a concern.
Quinolone antibiotics are known to have desirable antimicrobial properties. For example, quinolone compounds for use in the treatment of ophthalmic, otic, and nasal conditions are disclosed in U.S. Pat. No. 6,716,830, the entire contents of which are incorporated by reference herein.
Finafloxacin has been described as useful in the treatment of H. pylori infections. Buissonniere et al., “Antimicrobial activity of a new fluoroquinolone, finafloxacin, against H. Pylori in comparison to levofloxacin” Helicobacter, Vol. 13(5):465, October 2008; U.S. Pat. No. 6,133,260 to Matzke et al. Ophthalmic, otic, and nasal applications of finafloxacin are not described.
To cite one of many applications, the use of compositions having antimicrobial properties is important for the treatment of ophthalmic infections such as conjunctivitis. Conjunctivitis can be caused by various kinds of microbes, with most cases being due to bacteria and/or viruses. Unfortunately, conjunctivitis symptoms are not specific to the etiology of the infectious agent and significant testing may be required to determine the causative agent or microbe. Care must be taken in selecting appropriate agents for treating conjunctivitis, given the sensitive tissues affected by the infection. In view of the above-recited difficulties in treatment, compositions for treating conjunctivitis are needed that have broad-spectrum antimicrobial properties, a benign toxicological profile, and/or characteristics that prevent the transmission of contagious infectious agents.
Otic infections such as acute otitis externa (AOE) and acute otitis media with tympanostomy tubes (AOMT) are preferably treated by topical antimicrobial compositions, as the use of oral antimicrobials carries the risk of systemic side effects, and can occasionally fail to eradicate such infections with the possible development of drug-resistant strains. Recent years have seen a steady increase in quinolone-resistant strains of Staphylococcus and Pseudomonas bacteria, the most common causes of otic infections. In some areas, more than half of Pseudomonas strains isolated from otic infections are quinolone resistant. See Ballenger's Otorhinolaryngology: Head and Neck Surgery, Snow. J. et al., page 194, (2009). In addition, the external ear is generally an acidic environment due to the presence of cerumen. There is accordingly a need for additional topical compositions for the treatment of otic infection that are efficacious at low pH.